27 January 2010

When snails were insects

Here is the title of a letter from the polymath scientist Dr. Martin Lister published in Philosophical Transactions in 1674 (vol. 9, pp. 96-99).


Note that the phrase "those insects" refers to snails. Yes, back then snails were insects. But that didn't mean that the pioneering scientists of the 17th century thought that snails and insects didn't differ much. Lister et al. were refined enough in that respect—but not in other respects—to know that the 2 groups were sufficiently different. But to them the word insect seems to have had a more inclusive meaning; it meant invertebrate. Therefore, snails were insects.

This usage seems to have continued at least until the end of the 18th century. For example, an anonymous compilation from 1792 titled The natural history of insects had 16 chapters on insects proper.


In addition, there were two chapters on spiders, scorpions, centipes, etc., and one on various worms. Finally, the last one was on snails. In 1792 snails were still insects.


I don't know when the word invertebrate came into use.


DPC said...

This is very interesting. Three-quarters of a century later Linne would divide the invertebrates into 'Insecta' and 'Vermes' and include the snails in the latter category.

Anonymous said...

My 2-volume micro edition of the OED says that the first similar word in English was as part of the phrase "invertebral animals", first used in 1816, as a version of the French word "invertebres" (with accents I don't know how to do) which word was apparently coined by Lamarck in his 1809 book, "Philosophie Zoologique".

"Invertebrata" first appeared in an English context in 1828, and "invertebrate" appeared in 1838. The word "invertebrate" seems to have become well established by the late 19th century.


Susan J. Hewitt


David: Yes, Vermes was in use well into the 19th century.
Susan: Thanks for the clarification.

Deniz Bevan said...

Here's the etymology from the OED online: "[ad. mod.L. invertebrt-us, in neuter pl. INVERTEBRATA, corresp. to F. invertébrés (see below), f. L. in- (IN-3) + vertebra joint, esp. of the spine: see VERTEBRATE.
The classification of Vertebrate and Invertebrate Animals was primarily due to Lamarck; but in his Système des animaux sans vertèbres, 1801, he does not use the word invertébrés, which occurs however in his Philosophie Zoologique of 1809; it had been used by Cuvier and Duméril in 1805 (Cuvier Leçons d'Anatomie compar. I, Table I), and by Duméril, in 1806, in his Zoologie analytique, 3, Table I.]"


Thank you, Deniz. Long live Lamarck, the father of invertebrates!